Virulence Genes and Antibiotic Resistance Patterns of Bacillus cereus Isolated from Egyptian Milk, Milk Powder, and Ice Cream

Abstract

One of the most common food poisoning illnesses globally is caused by Bacillus cereus, which causes emetic and diarrheal food poisoning. Forty–two (42%) out of 100 samples from raw milk, powdered milk, ice cream, and pasteurized milk were positive for B. cereus, with a high prevalence in raw milk at 64%. Three virulence genes (nheA, cytK, and hblC genes) were characterized among 42 B. cereus isolates with variable frequencies. Detection of the nheA gene showed a high level of 90.4%, followed by the cytK gene in percentage at 50%, and the hblC gene at 47.6%. All examined strains were resistant to Penicillin, Oxacillin, then Cefixime and Ampicillin (85.7%), followed by Nalidixic acid (73.8%), Sulphamethoxazol-Trimethoprim(61.9%), and Oxytetracycline and Cephalotin (52.3%) whilst sensitive to Gentamicin (75%), followed by Enrofloxacin and Erythromycin (50%). Unfortunately, all examined strains are MDR and show 23 resistance patterns, this represents a real health malice for the people of Egypt. The obtained results demonstrated the rise of pathogenic B. cereus, a virulent organism that is multidrug-resistant, in Egypt's retail milk and milk products.